landscape data are either obtained from existing data bases (e.g. CORINE Landcover) or mapped in the field (usually [...] and indices for species richness, rarity, and, based on flower-visiting traits, the trait similarity
2018a). In addition, population estimates are based on expert judgement and a regular monitoring is [...] assemblages in the Danube is poorly known and often based on shoreline sampling (Szalóky et al., 2014). Hence [...] its conservation value and the lack of monitoring-based populations estimates, a special focus lies on the